Headless Exception Work-Around

On upgrading a piece of (1.4-dependent) server-side software from 1.4.2_01 to 1.4.2_14, I began seeing errors that looked like:

java.awt.HeadlessException
        at sun.java2d.HeadlessGraphicsEnvironment.getDefaultScreenDevice
            (HeadlessGraphicsEnvironment.java:66)
        at javax.swing.RepaintManager.getVolatileOffscreenBuffer
            (RepaintManager.java:537)
        at javax.swing.JComponent.paintDoubleBuffered(JComponent.java:4727)
        at javax.swing.JComponent.paint(JComponent.java:798)
        at edu.vt.cs.collab.cork.impl.servlet.CORKServlet.encodeComponentAsJPEG
            (CORKServlet.java:617)
        at org.isenhour.fin.inc.CEFChartWebView.writeChartImage(CEFChartWebView.java:97)
        at org.isenhour.fin.inc.CEFChartWebView.writeStaticContent(CEFChartWebView.java:84)
        at edu.vt.cs.collab.bridge.DefaultWebViewServlet.doGet(DefaultWebViewServlet.java:95)
        at edu.vt.cs.collab.cork.impl.servlet.CORKServlet.doGet(CORKServlet.java:293)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
        ....


The offending code segment was:

            img = new BufferedImage(sz.width, sz.height,
                BufferedImage.TYPE_INT_RGB);
            g = img.createGraphics();
            g.setColor(Color.white);
            g.fillRect(0, 0, sz.width, sz.height);
            comp.setBounds(0, 0, sz.width, sz.height);
            comp.paint(g);


where comp was a fairly uncomplicated Swing component. This turned out to be Sun bug 6189824. The work-around noted in the bug report, adding a call to:


    javax.swing.RepaintManager.currentManager(null).setDoubleBufferingEnabled(false);


seems to have fixed the problem.

16 June 2007 | Bug fixes | Comments

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Copyright 2003-2016 - Philip Isenhour - All code samples may be freely used under the MIT Open-Source License